Selector mechanism for radio apparatus



Dean. 6, W49 J. c. CLARK 2,499,619

SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1945 11 Shets-Sheet 1 7 ENVENTOR a": mil-aw:

* BY /mw ATTORNEY a W v G l a Dec. 6, 1949 J. c. CLARK 2,499,639

SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 ll Sheets-Sheet 2 w BY N /wue/z/ ATTORNEY Dec 6, 1949 .J. c. CLARK SELECTOR MECHANISM FOR RADIO APPARATUS ll Sheets-Sheet 3 Filed Dec. 27, 1943 BY wz ATTORNEY Dacv 6, 1949 J. c. CLARK ZAQEMHQ SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 ll Sheets-Sheet 4 INVENOR ATTORNEY Jls gpk/ a Dec. 6, W49 .1. c. CLARK 2,4 %,6w

SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 ll Shee'ts-Sheet 5 INVENTOR m epi a @Wfi ATTOR N EY Dec. 6, 1949 J. c. CLARK 2,490,619

SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 11 Sheets-$heet 6 (vi ii INVENTOR ATTORNEY' Deco Q, 1949 J, g, (:LARK 2,499,619

SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 ll Sheets-Sheet 7 INVENTOR wflgnvb a UW/E BY ATTORNEY Deco $5 N4 9 [llIIF llllllllllllvllllflgl lljllll l lllllHll J. c. CLARK SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 11 Sheets-Sheet 8 INVENIOR ATTORNEY Jw ha aw Dec. 6, 1949 J. c. CLARK SELECTOR MECHANISM FOR RADIO APPARATUS ll Sheets-Sheet 9 Filed Dec. 27, 1943 INVETO I I fih as g r ATTORNEY Dec; 6, 3949 I J. c. CLARK 2,490,619

SELECTOR MECHANISM FOR RADIO APPARATUS Filed Dec. 27, 1943 ll Sheets-Sheet l0 4 ATTORNEY Dec. 6, 1949 J. c. CLARK SELECTOR MECHANISM FOR RADIO APPARATUS ll Sheets-Sheet 11 Filed Dec. 27, 1943 ATTORNEY Patented Dec. 6, 1949 SELECTOR MECHANISM FOR RADIO APPARATUS Joseph 0. Clark, Merchantville, N. J assignor to Radio Corporation of America, a corporation of Delaware Application December 27, 1943, Serial No. 515,857

29 Claims. 1

My present invention relates to a selector mechanism for radio apparatus, and more particularly to mechanism for automatically and selectively adjusting the tuning device of a radio receiver or the like to preset positions whereby one of a number of predetermined radio transmitting station-s may be tuned-in rapidly and accurately from a remote control point.

An object of the invention is to provide a motor-actuated selector mechanism, operation of which is initiated at a remote point by rotary switch means or a series of push-buttons.

Another object of the invention is to provide a Selector mechanism of the type above mentioned which may be conditioned from a remote point to provide manual tuning either at the receiver or at the remote point.

A further object is to provide a selector mechanism capable of automatic operation for effecting adjustment of a controlled device to a limited number of predetermined fixed positions, and capable also of manual operation for effecting adjustment of the device to a multiplicity of positions, the mechanism being further provided with means at a remote point for selecting the manner of operation and then carrying out the selected manner of operation from the remote point.

A still further object is to provide automatic mechanism for selectively adjusting a device to one of a plurality of predetermined positions, the mechanism comprising a plurality of stopdisc-s mechanically coupled to the device each corresponding to one of said positions, a plurality of locking key-s each adapted to cooperate with 3 a corresponding stop-disc, key selector means operative to select the particular key to be efiective in determining the desired adjusted position of the device, key actuating means for moving the selected key into engagement with its corresponding stop-disc, an electric motor, a master gear driven by the motor, means for individually coupling the key selector means, the key actuating means and the stop-discs to the master gear to be driven therefrom, and means for making the individual coupling means efiective in proper sequence whereby the key selector means is first operated to a predetermined position to select a particular key, after which the key actuating means is operated to cause the selected key to move into engagment with its associated stopdisc, and then said stop-disc is moved into looking engagement with the selected key at which time the device will assume its predetermined adjusted position.

Another object is to provide a solenoid-actuated gear for eiiecting the coupling between the motor-actuated master gear and the several means driven therefrom, the several solenoids being included in an electro-mechanical system which functions to eiTect the proper sequence of operation.

Still a further object is to provide a selector mechanism which is capable of adjusting the receiver to a plurality of predetermined stations even though they are included in different frequency bands, band-switching being accomplished automatically in going from a previously tunedin station in one band to a desired predetermined station in another band.

And, still a further object of the invention is to provide a selector mechanism of the type mentioned which is positive in action, simple to operate, of compact construction, .and of light weight, such that it may be suitable for use with aircraft receivers where these characteristics are especially important.

The novel features characteristic of my invention are set' forth with particularity in the appended claims. The invention itself, however, as to both its organization and mode of operation together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawing, in which:

Fig. 1 is a view in perspective of the automatic selector mechanism embodying the present invention;

Fig. 2 is a cross-sectional view taken along the line 2-2 of Fig. 1;

Fig. 3 is a view, partly in section, taken along the line 3-3 of Fig. 2;

Fig. 4 is a view in cross-section of the selector disc stack and certain related parts;

Fig. 5 is an end view of the selector stack as viewed from the right of Fig. 4;

Figs. 6A and 6B are, respectively, front elevational and end views of the selector drum;

Figs. 7A to show the relative disposition of a selector disc, a key lever, selector drum and slide bar during a cycle of operation of the selector mechanism;

Fig. 8 is an end view of the selector unit, taken along line 88 of Fig. 2;

. Fig. 9 is an end view of the selector unit, taken along the line 9-9 of Fig. 2;

Fig. 10 is a side view of the selector unit as seen from the left in Fig. 3;

Fig. 11 is a view in front elevation showing diagrammatically the shiftable solenoid gears in position relative to the ring gear;

Fig. 12 is a side view of Fig. 1 showing certain additional elements under the control of the various solenoids;

Fig. 13 is a view showing the mechanism for oscillating the disc stack assembly;

Fig. 14 is a top view of the selector device with certain parts removed;

Fig. 15 is a view in cross-section taken on line il5 of Fig. 14 showing details of construction of the slide assembly;

Fig. 16 is a front view of the manual disc and shift lever assembly, as viewed from the right of Fig.

Fig. 17 is a side view of the assembly shown in Fig. 16 with certain parts added and other parts shown diagrammatically for the sake of simplicity; and

Fig. 18 is a schematic diagram of the electrical circuit utilized in the operation of the automatic selector device.

In general, the selector mechanism of. the present invention comprises a stack of individuallyadjustable selector discs corresponding to the number of stations to be automatically tuned, the

disc stack being mechanically coupled as a unita'ry device to the tuning device of the receiver -tobe controlled; a corresponding number of pivoted keys each of which is adapted upon actuati'on to lock the disc stack in a predetermined angular position; and a selector drum for determining the particular locking key to be actuated.

Each disc is provided at one point in its periphery with a suitably shaped notch, the angular setting of which determines the position to which the tuning device is to be automatically actuated. The keys are pivoted on a common shaft,-each having one end shaped to engage the notch of its radialdirection around the drum.

The selector drum is first rotated to one of a plurality of adjusted positions corresponding to a particular switch position or push-button at the remote point. In such adjusted position, one of the drum projections will move its corresponding key to a slightly raised position. A slide bar is then actuated to lift the key still further so that its shaped end rides on the periphery of its corresponding disc. As long as the key is in the latter position, the stack disc assembly is caused, by suitable means, to oscillate back and forth until the shaped end of the key drops into the disc notch. When thisoccurs the means for oscillating the disc assembly is made inefiective and, due to further movement of the slide bar, the shaped end of the key is forced home into the disc notch. The disc assembly will then be in a position of rest, and the tuning device being mechanically coupled thereto will have been moved to its preset position of adjustment.

In addition to the above described automatic operation, suitable means are provided whereby the selector mechanism is made ineffective so that the tuning device'may be actuated, either locally or from a remote point, to any desired position by manual control, means also being provided at the remote point for switching to the desired opcrating band.

able inductance of the moving core type, etc.

From the front of the casting there protrudes a shaft which carries a manual tuning knob or hand wheel 5 so that the receiver may be tuned locally by the operator. From the lower end of the side wall there extends a bushing 8 which houses a spline to which a flexible shaft 6' is adapted for connection so that manual tunin may be accomplished from a remote point. A rocker shaft 7 extends between side walls of the casting, and a lever 8 is keyed to the extended end at the left for the purpose of making preliminary adjustments in the selector unit as will be described hereinafter. A mum-conductor cable 9 extends from the rear of the selector unit and terminates in a control box at aremote: point.

Formed integrally with the casting or otherwise attached thereto are a plurality of tapped portions f0 which enable the selector deviceto be mountedin position, for" example behind the front panel of the receiver. Shown also in this figure are four solenoids to be more-fully described later but which for the present will be designated as follows: H, the oscillating solenoid; I 2, the selectordrum solenoid; 13, the segregating or slide bar solenoid; and M, the band-switch solenoid.

In Fig. 2 the selector unit 2 is shown to comprise a front plate 26, an intermediate or second plate 15' and a rear plate '16- dispo's'ed in parallel spaced relation and within which suitable bearings are formed for receiving a main shaft 11 which extends somewhat beyond the end plates. The second plate is supported from the rear of the casting l by a plurality of bolts, one of which is shown at It. The shaft I! is adapted to have mounted thereon, between the second and rear plates l5, l6, the selector disc stack assembly shown generally at H? to be described morefully in connection with Figs. 4 and 5.

The extended end of shaft 11, at the right in Fig. 2, has connected thereto fork assembly 19, shown more particularly in Fig; '9, consisting ofa casting having a rigid arm l9 and a resilient arm l9" urged together by a spring 20 for clamping a pin 4 projecting from an arm 4" affixed tothe variable member of the condenser. The action of the. resilient member pressing/pin. 4' against the rigid member [9' of the fork eliminates back-lash or lost motion between the selector and the condenser. This construction, as well as assuring exact one-to-one movement between the-selector and the condenser, permits a reasonable'amount of misalignment between them, which is unavoidable in certain types of installations.

The extended end ofthe shaft, at the left, carries a gear 2| which meshes with a second gear 32 affixed to a sleeve 23, to the forwardendof which thereis aflixed a circular indicator dial zit-having station or frequency calibrations thereon. The tuning condenser employed is capable of rotation through only degrees. In order to utilize the full scale of dial 24 and to spread the graduations thereon as far as possible, the dialnis geared up with respect to the condenser in a ratio of 15 to 8, through them'edium'of gear '22 having 32 teeth meshing with pinion 2| having 60 teeth.

concentrically arranged with respect to the dial 24 is a second dial 25 which serves to indicate the band to which the receiver is set. Mounted on the front plate 26 are the above mentioned solenoids H to I 4. Disposed between the plates I and 26 is a fixed bearing on which there is rotatably mounted a ring gear 21 adapted to be driven through a suitable gear train from an electric motor which serves to operate the selector mechanism.

In Fig. 3 the ring gear 21, shown in front elevation and partly in section, is driven through a gear train 28 to 3! from a uni-directional electric motor (not shown). As best shown in Fig. 14, gear 3| is mounted between plates l5 and 26 on the end of a shaft 32 which has its other end journaled in rear plate l6. Shaft 32 is motordriven through the medium of a worm gear 32' mounted thereon in mesh with a worm 32 carried on the motor shaft.

A stationary disc member 21 af'fixed to plate I5 and arranged in concentric relation with the shaft l1 serves as the bearing for the ring gear. In order to provide almost frictionless contact between the gear and disc member, the bearing surfaces thereof are formed as a raceway 38 containing the ball bearings 34. A rim member 35 (Figs. 2 and 3) is attached to the stationary disc member 2'! for retaining the ball bearings within the raceway.

Disposed around the periphery of the gear 21 are the gears 36, 31, 3B and 39 which are associated respectively with the solenoids ll, l2, l3 and M. The solenoids being mounted forwardly of the ring gear 21 on plate 26, they will not be seen in the view of Fig. 3, but in order that they may be shown in their relative positions and in association with their respective gears, they are represented in this figure by the dotted circles. The gears 36-39 normally do not mesh with the ring gear, being disposed in the space between plate 25 and gear 21 as shown in Fig. 2 for the solenoid gear 38. Upon the energization of the solenoids, however, at predetermined times in the cycle of operation, the respective gears will each be forced into meshing relation with the ring gear.

Shown also in Fig. 3 in dotted outline is an end view of the selector disc assembly [8, a key lever 46 and a selector drum 5!, now to be described more fully in connection with Figs. 4 to 6.

The disc assembly l8 comprises a stack of discs 42, the number thereof being equal to the number of stations for which it is desired to provide automatic tuning. There are ten such discls shown in the present embodiment, although it will be understood that the number can be varied to suit the requirements of the installation.

The several selector discs are mounted on individual bushings 43 which are clamped against rotation on the shaft l1. Also clamped to the shaft and extending from between adjacent bushings to the periphery of adjacent discs are thin wafers or washers 44. To the right of the disc stack is a disc 45 of larger diameter and to the right of the latter disc there is positioned a bowed dish-like spring 46. With this construction the discs of the stack assembly are free to turn radially when not compressed axially by the pressure exerted by the spring 46, but are clamped in position rigidly by this spring under normal conditions. The purpose of the wafers 44 separating each of discs is to prevent the rotation of any one disc fromaffecting the position of an adjacent disc. 1

At the left end of the stack is a disc 4'! of the same diameter as discs 42 which is rigidly attached to the shaft I"! by key means or otherwise. A shiftable disc assembly 41', employed to condition the mechanism for manual tuning is mounted to the left of the end disc on a reduced portion of shaft [1. An elongated slot 48 is formed in the surface of disc 41 to accomplish this function as will be described later.

A gear 49 provided with an internally threaded hub 50 is adapted to be screwed home onto the threaded portion 5| of shaft I! in order that the bushings and the washers may be clamped together rigidly as a unit. In a manner to be explained hereinafter a pair of rollers 52 may be moved to the right as viewed in Figs. 2 and 4 to apply pressure to the larger disc 45 to urge it to the right against the action of spring 46 so that any one of the discs 42 may be rotated to a desired angular setting. Each selector discis provided at one point in its periphery with a V-shaped notch 53, shown in Figs. 2 and 5, the particular radial setting of which determines the angular position of the device to be adjusted.

The shaft H is provided with a reduced portion 54 on which there is seated a gear 55 which is driven by suitable means to oscillate the stack assembly 18. Interposed between the gear 55 and the stack assembly is a friction drive device constituted by a plate member 56 attached to gear 55 and a cooperating plate member 51 attached to the gear 49.

Pivotally mounted on a shaft 58 which extends in parallel relation with the disc assembly shaft l'! are the key levers 40 above mentioned, one for each selector disc, corresponding levers and discs being aligned with one another in a vertical plane. The key levers each have the configuration shown for example in Figs. 7A to 70, one end being provided with a head portion 59 and the other end with a tail portion 60. It will be noted that the aperture 6| in the key lever through which the shaft extends is not circular but elongated somewhat in a direction transverse to the length of the key and wedge-shaped for a purpose to be described later.

The selector drum 4| is positioned just below the tail ends 60 of the key levers, extending transversely and in parallel relation with the shafts l1 and 58. A side elevation of the drum is shown in Fig. 6A and a front view in Fig. 63 from which it will be seen that there are arranged on the surface thereof a series of pins or projections 62 which are spaced in an axial direction corresponding to the spacing between the key levers, and spaced apart equally in a radial direction, the several pins forming a spiral around the drum. There are 11 such pins, 10 of which are effective to provide automatic operation, and the 11th, the one on the extreme left in Fig. 6A referenced 62, being used to effect manual control in a manner to be described.

The drum is provided on opposite sides with trunnions 4| which are adapted to fit into bearings formed in the intermediate and rear plates I5, l6 of the selector unit so that the drum may be rotated about its axis when actuated by suitable driving means. Mounted on the left-hand trunnion (Fig. 10) for rotation with the drum is a ll-position detent wheel 63 (corresponding to 10 automatic positions and a manual position) which, in cooperation with a pivoted detent lever 63' urged into engagement with one of the wheel in a clockwise direction about its shaft.

'19 of the slide bar carrier arms.

see ers 7 detents by a spring 63" (Fig. 9), is effective to maintain the drum in any position to which it maybe 'rot'ated.

In Figs. 7A to 7C are illustrated the successive positions of a selector disc 42 and of its corresponding key lever and selector pin during a cycle of operation. In the position shown in Fig. 7A the tail end 50 of the lever will ride on the surface of the drum and the head end 59 will be elevated slightly above the periphery of the disc by reason of pressure applied to the lower part'of the lever. by a leaf spring 64. Assume now that the drum is rotated in the direction of the arrow to the position shown in Fig. 7B. In moving to this position the pin 62 will apply a forceto the tail end of the key lever which will rock slightly At thistime a knife-edged slide bar or segregating bar 65' is brought up to bear against the underside of the tail end of the lever with considerable force,

overpowering spring M, and causing the particular key which has been segregated from the others to rock still further. This causes the head end of the key to approach its particular selector disc, either coming to rest somewhere on the periphery of the disc or forcing itself into the V-shaped notch, if the disc stack were already turned to nearly the correct position. With the key head falling on the periphery of the disc the disc stack is oscillated back and forth by means hereinafter to be described, until the notch 53 of the particular disc arrives underneath or in registry with the key head, causing the lever to rock still further about its pivot, at which time the oscillatingmeans will cease to function. Due

to the continued pressure of the slide bar, however; the head end of the key'lever will be wedged into the disc notch, 53, and the mid-section of the lever will be raised slightly to permit the lower portion of the aperture BI to firmly hug the l shaft.v In the home position of the disc shown in Fig;. 7C the disc will be locked against rotation and'in the angular position for which it was set.

The mechanism for actuating the segregating bar 65 will nowbe described in connection with Figs. 8, 9 and 10, the first two beingviews taken respectively along the lines 8-8 and 9-9 in Fig. 2, and the third being a View looked at from the left. in Fig. 3. Pivoted at 66 to the outer surfaces of both the second and rear plates and [6 are a pair of arms 97, 58, respectively, which areof similar configuration, except for an arcuate extension 59 on the front arm 61. The arms are provided each with an upstanding portion Hi to which aforce is adapted to be applied for moving the arms downwardly, through an are about their pivotal points 3'5, against the action of a pair of springs H only one of which is shown in Fig. 8. Carried by the arms and extending therebetween through an arcuate cut-out 12 in each of the plates is the segregating or slide bar 65 previously mentioned.

Suitably journaled on the outer surfaces of plates l5, l6 are a pair-of gears 53, F4, respectively,which are adapted to be driven simultaneously from the ring gear when the slide bar solenoid i3 is-energized. Each gear carries a cam 15, the two being similarly shaped, as shown, and phased to coac't simultaneously with the upright extensions The gear 14 on the rear plate carries in addition a crown cam lfiprovided at one portion of its circumference with a sloped notch or depression i1. With the crown cam in the position shownin Fig. 9, which is itspositionof rest, the notch will receive a pin 18 which is adapted upon being lifted out of the notch by rotation of the crown cam to close a switch 79' connected in circuit with the slide solenoid l3. Carried at one end of the rear carrier arm 68 is a pin which, in a particular angular position of the arm, is adapted to coact with a leaf spring 8| on which there is carried the movable contact 82 of a switch 83 included in circuit-with the oscillating solenoid I I.

The mechanism for actuating the several component parts of the selector unit in timed relation will now be described in connection with Figs. 11 and 12 which illustrate diagrammatically the cooperative relation between said parts. Arranged around the ring gear 21 are the solenoid-actuated gears 36 to 39. Normally these gears do not mesh with the ring gear, the latter being continuously rotated so long as the motor drive is effective. The normal inoperative position of solenoid gears 36 to 38 is shown in Fig. 12. Attached to the armature of the drum solenoid i2 is a spindle 84, the end adjacent the solenoid carrying the gear 37 and its opposite or outer end protruding through an aperture in the rear plate 46. The armature of the solenoid l3 which actuates the segregatin bar carrier arms has the gear 38 attached thereto which is adapted when actuated to mesh with a gear 38' mounted at one end of a spindle journaled in the plates l5, 16. A similar gear 38' is mounted at the other end of spindle 35, and in mesh with gears 38', 38 are the respective cam gears 13, Hi. The armature of the solenoid ll which oscillates the disc stack assembly is also provided with a spindle 86 journaled in the plates 15, iii, the end adjacent the solenoid carrying the gear 36 and the opposite end carrying the gear 35.

In initiating operation at the remote control point, as by setting a rotary switch or pushing a button, the drum solenoid i2 is first energized so that the tendency of its shaft or spindle 3A is to move to the left, as viewed in Fig. 12. But this action is restricted by reason of the arcuate extension 69 on the carrier arm ti (see Fig. 8) which in the first instance is in a raised position. The gear 3'! is, therefore, prevented at this time from meshing with ring gear 21. The spindle 84 will, however, be permitted to move sufficiently to the left to close the contacts of switch 18 (see Figs. 9 and 18) which is included in the circuit of solenoid 13. The latter will now be energized to cause the shifting of the solenoid gear 38 to the left, as viewed in Fig. 12, into meshing engagement with both the ring gear 2'5 and the right hand gear 33. As a consequence, gears i3, M will be driven from the ring gear and the cams 15 will rotate to coact with the upright arm extensions it) so that the slide bar carrier arms 51, 68 will be swung downwardly about their pivots 63. Durin the initial movement of the carrier arms, the extension 69 will be withdrawn to permit the gear 3? associated with the drum solenoid l2 to complete its axial movement to the left, thereby permitting meshing engagement between gear 3'! and ring gear 21 and also with a gear ill" carried by the selector drum ti. As a result the drum will be caused to rotate until it arrives at a position determined by a homing switch 3? (shown diagrammatically in Fig. 10) movable with the drum, to be described more fully in connection with the schematic circuit diagram of Fig. 18.

Phe function of crown cam 13 is to raise pin 18 to circuit closing position even beyond the point where it is raised by spindle 84 upon energization 75- of drum solenoid l2, thus keeping slide bar'solenoid l3 energized while crown cam I8 is making a complete revolution, even though drum solenoid I 2 has become deenergized because of the homing switch having found its open circuit.

The selector drum and slide bar operate in a definite timed relation. The gear ratio of the several gears associated with solenoids I2 and I3 is so chosen that the speed with which drum 4| rotates is twice the speed with which gears 13, I4 rotate. Therefore, once gears I3, I4 have started to rotate and the slide bar is withdrawn, drum M is able to make a complete revolution and come to rest before gears I3, I4 and their associated cams have made their complete revolution.

As previously described, the particular angular position at which the drum 4! is stopped determines which one of the key levers 40 is to be effective in bringing about the automatic adjustment of the disc stack assembly to a predetermined position. Upon completion of one revolution of the cams I5, the carrier arms will be returned to an upward position by action of the spring I I, and the segregating or slide bar 65 will be cause to ride under the tail end of the raised key lever and above the tail ends of the remaining levers, as previously described with reference to Figs. 7A to 7G. The head portion 58 of the key lever will now ride on the periphery of the associated disc, and in the position of the carrier arms which permits this, the pin 80 on the rear carrier arm 68 (Fig. 9) will force the spring leaf 8I upwardly to close switch 83. As a result, oscillating solenoid l I will be energized and spindle 88 will move axially to the left, resulting in gear 38 at the right being driven from ring gear 21 and the gear 36' at the left meshing with a gear 88 carried on the rear plate I8. Through the medium of suitable means actuated by gear 88, the disc stack assembly is oscillated 'back and forth until the peripheral notch in the selected disc is brought into locking engagement with the operated key as previously described with reference to Figs. 7A to 7G. With the key seated or locked in engagement with its disc, the segregating bar is urged to move upwardly still further by action of its spring I I, and pin 80 being movable with the segregating bar moves out of engagement with spring leaf 8| to break the circuit through solenoid I! thereby stopping operation of the oscillatin means.

The arrangement whereby the disc stack and condenser are made to oscillate is shown in Fig. 13. The second small pinion 36' mounted on the spindle of solenoid II engages the gear 88 as mentioned above in connection with Fig. 12. An eccentric pin 88 carried on the gear supports one end of a connecting link 90 which has its other end pivotally mounted on a gear segment 9! at point 92. The gear segment itself is pivoted at 93 on rear plate I6 and meshes with the gear 55 which is associated with the stack assembly (Fig. 4). It will be seen therefore that while solenoid H is energized, gear 88 will rotate to drive the connecting link back and forth, which in turn will oscillate gear segment 9|, pinion 55 and eventually the disc stack and the condenser associated therewith. Through the medium of disc 56 Which is rigidly attached to gear 55 and friction drive 51 which is rigidly attached to gear 49 of the stack assembly, the driving relation between the crank gear 88 and the stack is a friction drive and therefore not entirely positive, thus permitting the oscillating drive to urge the stack and condenser to oscillate slightly more than 180 degrees, although it cannot do so because of limiting stops on the condenser. This 1'0 prevents a power build-up from the driving motor through to the condenser which might jam when a key is seated into a disc notch.

In order to initially adjust the mechanism to an automatic position the set-up lever 8 (Figs. 1 and 14) is first pulled forwardly which can be done conveniently with a finger of-the left hand; Pulling this lever rotates the shaft I which carries a link member 84 as a crank arm. Attached to link 94 is a link 95 which moves rearwardly and axially to the stack shaft l1 and inturn causes a yoke 96 to swing rearwardly b reason of its arms being pivoted on a pair of pins carried on a fixed support, only one of which is shown at 91'. Yoke 95 carries the rollers 52, previously mentioned, which due to manipulation of lever 8 presses against disc 45 of the stack assembly, depressing the spring 46 and relieving the clamping of discs 42. At the time this lever is operated one of the automatic positions has been selected, and therefore one of the discs 42 is rigidly held in position. At this time the knob or hand wheel 5 (Figs. 1 and 14) attached to a shaft 81 is rotated and, through the medium of a gear 98 mounted thereon, an idler 99 mounted on a. slide I00, and idlers IM and Ifll, drives gear 49 ofthe stack assembly, thus rotating the tuning con-' denser and all the discs of the stack except the one that has been engaged by a key. Upon re-' lease of lever 8 the driving relation between shaft 91 and the stack is removed, and the pressure on the several discs 42 is-restored to clamp them all to the stack.

The yoke 86 carries a pin I02 which is adapted to be received between a pair of disc plates I03 forming a part of the slide I00 on which the-idler 99 is mounted. As shown more clearly in Fig.

. 15, which is a view in cross-section taken on line I5-I5 of Fig. 14, the slide is movable on a. shaft I04 which carries a guide pin I05 extending through a slot I06 in the slide. Between said pin and a second pin I01 carried by the slide there is connected a coiled spring I 00 which tends to retain the slide in a forward position, as viewed in Fig. 14, or to the right as viewed in Fig. 15.

It will be seen, therefore, that simultaneously with the rearward movement of the yoke 96, due to the manipulation of the set-up lever 8, the slide I00 will be moved rearwardly due to'its engagement with the pin I02'to bring idler 98 into meshing relation with gears 98 and IN, as pre viously mentioned. The slide I00 carries on its forward end a gear I09 which in the normal position of the slide as shown in Fig. 14 meshes with 3.1gear H0 carried on the manual control shaft The knob or hand wheel 5 is used for the dual purpose of setting up the automatic positions in. the manner described above and of locally tuning the condenser in a manner now to be described when the mechanismis set for manual operation. The shaft I04 carries at its forward end a beveled gear I I I which meshes with a second beveled gear H2 carried at one end of a shaft II3 which is journaled in bearings H4, H5 (Figs. 1 and 3). The opposite end of shaft H3 carries a beveled gear H6 which meshes with a beveled gear ll! affixed to spline 6. When theset-up lever B is released and the knob 5 is rotated, it will be seen that spline 8 willbe rotated through the gear train comprising the gears H0, I09, III, II 2, H6, and II], -and, through the medium of the flexible shaft 6' attached at one end to the spline and terminating at its other end in a control the shiftable .d-isc assembly 41"., previously mentinned with reference to Fi 4, so that the latter may .be rotated in response to .either of the mancontro s- The shiftable -nanual disc assembly 41' comprises 1 ring gear -I23 which is adapted to mesh with. split gear I21 {and is force nttedor otherwise attached to a disc member I24 having a peripherial surface I24 of the same diameter as discs .42 of the stack and a second peripheral surface 424" of slightly reduced diameter. The

assembly further provided with a hub membe): 125 having a circular groove I25 :formed in its periphery and a. tapered pin I26 carried by disc I124 on its side facing the end disc 41.

A coiled spring J26 concentrically arranged on the-reduced end of shaft 511 between hub I25 and plate 5| 5 tends to wise the disc assembly 123-425 towards t e end disc 41, to the left .as viewed in. F 3 In order to permit shifting of the d s assembly towards the and d s and to return he some to the d sen a ed position shown. in F le and to re a l; Jim-that position. there is provided a forked lever I21 pivoted at po nts .l :.2.1:'. The .iorkcd and 1.2.8 of the lever is disposed within the groove. I 25' of hub I25 and its pposite nd i p oyided with a rearwardlyp jecting arm .129 and a downwardly projecting formed part =1 3;! which is adapted to be engaged position such that the elongated slot 48 in end disc 41 is aligned or in registry with pin I26, the stack assembly is oscillated through its range until such alignment takes place whereupon the pin is caused to drop into the slot. The additional shifting movement of the disc I24 brought about by the pin dropping into the slot is sufficient to cause the 11th key to drop from the larger periphery I24 to the smaller periphery I24 so that, in a manner analogous to an automatic key being wedged into a disc notch, operation of the oscillating mechanism is stopped by opening the circuit of oscillating solenoid II at switch 83.

With the shiftable disc assembly I23-I25 locked in engagement with the disc stack and the split gear I 21 being continuously in mesh with the ring gear I23, a mechanical drive is established between worm H8 and the stack to permit thereby direct tuning of the condenser either by knob 5 locally, or by way of the flexible by a pin. 13.3 attached to the carrier arm 61 .at

the front .of the unit.

An 11th key I3;l (Figs. 8, L6 and 17), similar to the .10 automatic key 4.0 and also mounted on key shaft .58, is associated with the .shiftable disc assembly and with the retaining and shiftinglever I21. The key is provided .at its tail end with a headed rivet I32 which is adapted to enease arm I29 of the lever. During the automatic Operation of the selector mechanism the 11th or manual key will assume the position shown in Fig. .16. by reason of .itsspr'ing 64' which is similar to the several springs 5.4 individually associated with the several automatic .keys .40. In that position the rivet I32 at the tail end of the key will engage arm I29 of lever I21 and the heady end. will be raised slightly above the periphery I24 ofdisc 24.

When it is desired .to .conditipn the selector me hani m or manu operation. the control switch at the remote point, to be described later in connection with Fig. 18, is set to a manual position. As a result, the selector drum is rotated to a position whereby its 11th projection 62- is effective to move the 11th key about its shaft in a clockwise direction. This key movement causes the rivet I32 to become disengaged froma-rm I2}! and causes also the head end of the key to ride on the disc periphery 124'. The disengagement of arm I29 permits th axial shifting of disc assembly I23I25 towards end disc 41 due to the action of spring I25, and the disposition of the key head on I24 initiates operation of the oscillating mechanism for the. stack assembly I9 in a manner similar to that brought about by the -10 automatic position keys. Unless the stack assembly happens to be in a cable 6" from a remote control box.

In the locked position between the shiftable disc assembly and the stack the segregating bar 65 is in its uppermost or initial position as shown in Fig. 70. Subsequent operation of the remote control switch to rcconolition the selector mechanism for automatic operation causes the segregating bar carrier arms 61, 68 to swing downwardly about their pivotal points as described previously with reference to the cycle of operation for automatic selection. With the removal of the segregating bar irom underneath the tail end- .of the 11th key, the spring 64- exerts sufiicient pressure to lift the head end of the key clear of disc I24 and to lower the tail end so that its rivet will be in a position to receive the shifting lever arm I29. Continued downward movement of the carrier arms causes the pin I33 on arm I61 to engage the formed part I30 of lever I21 to force the latter to swing about its pivots, the forked part I23 moving the disc assembly away from the stack in opposition to spring I26 and" the arm I29 moving towards rivet I32 to be engaged thereby. The locked engagement between parts I29 and 132 enables the shifting lever I21 to retain the disc assembly out of coupling engagement with the disc stack as shown in Fig. 17, and this condition will continue as long as the remote control switch is set to any one of the automatic positions and until the control switch is set to a manual position for operating the 11th key to effect the coupling engagement between the shiftable disc assembly and the disc stack .as explained above.

The operation of solenoid I4 is a distinctly separate function from the others. It is energized only when a change in band is required. The pinion 39 on its shaft is adapted to engage ring gear 21 to drive a shaft I34 which carries at its rear end a beveled gear I35 and at its forward end the band dial 25 (Fig. 2). Bevel I35 engages a second bevel I36 attached to a disc I31 which carries a pin I31 near its periphery. A slide rod I38 is connected between the pin I31 and suitable actuating means I38' for the band-switch (not shown) which is located in the receiver proper. A homing switch I39 movable with the band-switch and also operated by the slide rod completes the circuit through the band-switch solenoid I4 keeping it energized until the slide rod has shifted sufficiently to cause selection of the proper band called for by the homing switch. Simultaneously the dial 25 will be rotated to a position corresponding to the selected band, and

13 an indication thereof will be viewed through a suitable opening in the front panel of the selector device.

The electrical system of the selector mechanism above described is shown in Fig. 18. A control box I 40 located at a remote point contains a pair of rotary selector switches I41, I42 arranged in tandem, and with their respective movable arms I43, I44 mounted on a common shaft represented by the dotted line I45. Switch I4! is provided with contacts I to Ill, representing automatic positions, which are connected individually by way of conductors of the cable 9 to correspondingly numbered brush contacts of a switch wafer 81, said switch being further provided with contacts A to D, representing manual positions, which are connected together and to an 11th conductor II of the cable 9 which is connected to the brush contact II of the same wafer. The second switch I42 is provided with contacts A to D angularly disposed like contacts A to D and connected individually by way of cabled conductors I46 to I49 to a switchboard I56 housed in the upper part of casting I, the remaining contacts of the switch being blank.

It will be understood, of course, that in place of the rotary selector switches I4I, I42 there may be employed a system of push-buttons which would accomplish the same result.

The above-mentioned wafer 81 and Wafers 1;,

81", 81" constitute the homing switch 81 men tioned previously and shown schematically in Fig. 10. Switch wafer 81' consists of a conducting ring I provided with a cut-out or insulating portion I52 at one point in its periphery, and the switch wafers 81" and 81" consist each of a conducting ring I53 which is provided with a projection I54. The three switch wafers are mounted on a common shaft, and the two projections I54 and the portion I52 are phased as shown to assume the same angular position with rotation of the switch wafers.

The brush contacts I-IZ associated with wafer 81 are adapted to contact the ring I5i, the brush contact numbered I2 of this wafer being connected to the drum solenoid I2. The brush contacts I through II of the second wafer 81" are connected to the correspondingly numbered brush contacts of wafer 31' and are out of contact with the ring I53, but are adapted to contact successively with the projection I54 upon rotation thereof. The brush contacts I through I 6 of switch Wafer 81" are out of contact with its ring I53, but are adapted to contact successively with the projection I54 upon rotation thereof. The brush contacts I2 of the wafers 81" and 81" are in contact with their respective rings I53 and are electrically connected together. The contact brushes I through I 6 of switch wafer 81 are connected respectively with terminals I through II! of the band selector switchboard I 50.

The switchboard I56 is provided with a plurality of conductors, equal to the number of bands for which the receiver is designed, shown by way of example in the present embodiment as four bands and referred to hereinafter as the A, B, C and D bands. Said conductors may constitute extensions of the conductors I46 to I49 connected to switch I42 and are, therefore, similarly referenced. Each conductor has associated with it a plurality of contacts I55 which are aligned with the terminal contacts I to I6 and which are equal in number to the stations that are desired to have tuned-in automatically, there being in the present embodiment. By means of a flexible lead I56 from each of the terminal contacts I to I 6' the latter may be selectively connected to any one of the aligned contacts I of the conductors I46 to I49.

The switchboard conductors I46 to I49 each terminate respectively at one of the brush contacts A" to D" which are associated with a wafer I51 of the homing switch I39, the wafer consisting of a conducting ring I58 provided at one point in its periphery with a cut-out or insulating portion I55. The wafer I51 of the band homing switch does not move in unison with the homing switch 81 for station selection but is moved independently when required by the bandswitch solenoid I4 which is electrically connected to the brush contact I4 in contact with the ring I58.

A suitable source of energy for operating the mechanism is shown at I66. The terminal of the source is connected through a motor relay I6I and then by way of a conductor I62 to the conducting shaft I45 of switches I4I, I42, and by way of a conductor I to slide solenoid I3 and oscillating solenoid II through, respectively, switches 19 and 83, previously described. A m0- tor I64 is connected between the terminal of the source and ground through a grounded relay armature I65 when pulled up to the front contact I66 of the relay, the armature normally resting on the relay back contact I61.

The manner of automatic operation of the selector will now be described. At the remote control box the switch arm I43 will be adjusted to any desired position 1 through 10, let us say to the position 9, as shown, which corresponds to station No. 9. The circuit completed thereby will be from the terminal of the power source, through motor relay IEI, conductor I62, shaft I45, switch arm I43, contact 9, contact brush 9 of switch wafer 81', contact brush I2, drum solenoid I2, and to ground which is the negative side of the power source. As a result the motor relay I6I will pull up its armature to front contact I66 thereby closing the energizing circuit of operating motor I64 which begins to drive the ring gear 21. In actuating its armature to close the motor circuit the relay simultaneously breaks the cathode return circuit at contact I61 of one of the stages in the receiver, such as the second intermediate frequency (I. F.) stage, to thereby disable the receiver and to provide silent tuning during the automatic operation of the tuning mechanism.

The drum solenoid I 2 is also energized with the completion of the above circuit, but as previously explained the selector drum is not yet actuated due to the stop 69 on carrier arm 61 being in the path of gear 31 which prevents it from engaging with the ring gear. The immediate effect of solenoid I2 upon its energization is to close the switch 19 thereby completing the circuit for slide solenoid I3 which actuates the slide bar 65 through its cycle of operation as previously explained. With the initial movement of the slide bar the stop 69 is Withdrawn to permit the drum solenoid gear 31 to eifectively couple the selector drum to the ring gear. The drum will now begin to rotate as will also the homing switch 31 which is mechanically coupled thereto.

Upon the arrival of the homing switch wafer 81" to the position shown, the circuit of the drum solenoid will be broken at the brush contact 9 and the drum will stop at a position such that its projection 62 corresponding to station No. 9 will arrive underneath the key lever 66 associated therewith, as shown in Fig. 7B.

the 321681159.- of the my lever seats itself inithernotchoithe corresponding selector disc 42 the switch 83 will be closed by the pin BI! andthe oscillator solenoid II will be energized to allow itsgears 35, 36 to mesh respectively with the ringgear andthe geartrain previously described for effecting "the back and forth movement of the disc-stack assembly until the key head drops into the. notch :ofythe selector disc corresponding to station No. 9, whereupon the pin 88 will be moved away from its engagement with spring contact 81 to permitswitch B3 to open so that oscillating solenoid II will be .de-energized.

In the position of the switch wafer 875" of the homing switch a circuit .will be closed from the terminal of the energizing source, motor relay IBI, conductor I62, shaft I45, switch arm I43, contact 9015. switch I41, brush contact 9 of water. ST-firing I53 and brush contact I2 of the same wafer, brushucontact I2 of wafer 8'1"", ring I53 and brush contact 9' of the same wafer, terminal 9' of the switchboard I59, flexible conductoriifi, conductor"l46,'brush contact A" of homin-g switch wafer I51, ring I58 and brush contact I4" of said wafer, and band switch solenoid I4. The circuit above traced will then be closed to energize the band switch solenoid to cause the shifting of its gear 39 into coupling relation with the ring gear 21 toeffect movement of the band switch and the homing switch I3Q through the t intermediary of elements I34, I35, I36, I31, I31 and I38 described and shown in connection with Fig.2. Upon the arrival of homing switch wafer I 51 to the position shown (Fig. 1 8) the circuit ofband switch. solenoid I4 will be broken at the brush contact A, and the band switch of the receiver will have been rotated to the position required to adjust the receiver for station No. 9 which, due to the switchboard connection, is in the A hand.

If, however, the terminal 9' at the switchboard had been connected by means of the flexible conductor I56 to, let. us say, contact r55 on conductor I48 (which corresponds to the C band) the band switch would have been actuated by the solenoid I4 to a position such that the switch wafer I51 would be moved to a position in which its insulating portion I59 would .be opposite the brush contact C, in which position the circuit of solenoid I4 would be broken and the band switch set to band C.

It will be clear, however, that in automatically tuning the receiver from one station to another in the same band, as for example from No. 9 to No. 5, both being set up in switchboard for band A, the band switch solenoid I4 will remain inoperative, its circuit being open at brush contact ,A of homing switch wafer I57, and the band switch. at the receiver will remain idle, that is,,it will be set to the previously actuated band A position.

Other or the stations 1 to 10 may be tuned in automatically in a similar manner as explained above by merely selectively adjusting switch arm I43 at the remote control box-n one of the contaste I through In. The connections that are made in advanve at the switchboard determine the, particular band in which the respective stations are located. For example, station No. 1 is in band..A,.-station N0. 2 is in band- C, station No. 4 is in band ,3, station No. 3 is in bandvD, etc.

Alternatively, as heretofore mentioned, the device. may be conditioned for manual control from either the. remote point or locally at the receiver. In accomplishing this the switch arm I43 at the remote control box is moved to any one of the contacts A to D, depending upon the particular band within which it is desired to operate the receiver. In any case there will be completed a circuit similar to that described above in connection with contact 9 to energize the drum solenoid and efiect rotation of the selector drum to the position where its 11th projection 62 will actuate the 11th or manual key lever I-3I to initiate the shifting operation of the disc assembly i23-I25 previously described with reference to Figs. 16 and 17. Upon completion of the shifting operation a direct mechanical coupling will be provided between the disc stack assembly and the worm H8 (Figs. 1 and 17) which. permits the tuning device .of the receiver to be actuated either by manual control knob '5 at the receiver or by a manual control IE8 attached to the end of flexible cabled which terminates at the remote control box I40 or at an auxiliary control box.

In moving switcharm I43 toone of the manual positions A to D, switch arm I44 moving in unison therewith will contact the corresponding contact A to D. If it be assumed that manual tuning is desired to be had ;in the C band, "for example, switch arm I44 will be moved to its contact C to thereby close the following circuit: terminal of source IfiII, motor relay I56 I, conductor 82, shaft I45, switch arm I44 which is.

now on contact C, conductor I48, brushcontact C" of wafer .I:5,l,. conducting ring I58, brush contact I4 to band switch solenoid I4. As a result both motor I64 andsolenoid 1.4 will be energized, the former driving the ring gear 21 and the latter shifting its coupling gear .39 to mesh therewith, thereby operating the actuating bar I38 for the band-switch and the homing switch I39 as previously explained (Fig. '2). Upon rotation of homing switch wafer I51 to the position where its insulating or cut-out portion I 59 is opposite brush contact C" the abovedescribed circuit will be broken. Solenoid I4 and motor I64 will then be ole-energized and the bandswitch at the receiver will be adjusted to its C position, as desired.

It should be noted that there may be incorporated in the selector mechanism one or more additional solenoids, such as the solenoid I4 for example, for accomplishing other independent functions, such as band-width control, which may be associated .or disassociated with the sequence described above.

Although the invention has been described with particular reference to radio receiving ap paratus it will be apparent to one skilled in the art that the invention may be applied equally as well to transmitters or other apparatus in which it is desired to automatically adjust the settings of variable devices from a remote point, or to accomplish other functions such as the selective switching of elements, etc.

While I have shown a particular embodiment of my invention, it will, of course, be understood that I do not wish to be limited thereto, since various modifications may be made both in the circuit arrangement, in the instrumentalities, and in the mechanical construction employed without departing .from the spirit and, scope of my invention as set forth in the appended claims, and I contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim is:

1. Shaft positioning apparatus comprising, in combination, a shaft to be positioned, a stopdisc assembly mounted on the shaft comprising a plurality of stop-discs each of which corresponds to a different desired angular position of the shaft, a selector drum having a plurality of projections corresponding to the number of stop-discs, a series of keys cooperatively related with both said stop-disc assembly and said selector drum, each key being individually actuated by a separate drum projection for engagement with a corresponding individual stop-disc, driving means for said apparatus, individual means for coupling the selector drum and the stopdisc assembly to be driven independently from said driving means, and means for actuating said individual coupling means in a predetermined sequence of operations for actuating a selected key and for moving the corresponding stop-disc into locking engagement therewith for setting said shaft in desired angular position.

2. Shaft positioning apparatus in accordance with the invention defined in claim 1 wherein a unidirectional motor is utilized to actuate the driving means, and the means for actuating the stop-disc assembly from said driving means includes means for alternating the direction of r0- tation of said assembly.

3. Shaft positioning apparatus in accordance with the invention defined in claim 1 wherein the individual coupling means are electrically operated.

4. Shaft positioning apparatus comprising, in combination, a shaft to be positioned, a stop-disc assembly mounted on the shaft comprising a plurality of stop-discs each of which corresponds to a different desired angular position of the shaft,

a series of keys each cooperativel related with a corresponding sto -disc, a selector drum constructed and arranged to select the particular key to be effective, a slide bar for actuating the selected ke into locking engagement with its corresponding stop-disc, driving means for said apparatus, individual means for coupling the selector drum, the stop disc assembly and the slide bar to be driven independently from said driving means, and means for actuating said individual coupling means in a predetermined sequence of operations for selecting and then actuating a particular key and for moving the corresponding stop-disc into locking engagement therewith for setting said shaft in desired angular position.

5. Shaft positioning apparatus in accordance with the invention defined in claim 4 wherein the slide :bar has associated with it a stop member which, until the slide bar has been moved by actuation of its coupling means, prevents the actuation of the selector drum coupling means.

6. Shaft positioning apparatus comprising, in combination, a shaft to be positioned, a stop-disc mounted in adjusted relation on the shaft to be positioned, a key disposed in cooperative relation with said stop-disc, a cam device for moving the key towards the stop-disc to a limited extent, a slide bar for moving the key into engagement with said stop-disc, and means for drivin said cam device to effect the limited movement of said key, and for driving said slide bar to effect a further movement of said key, and for driving said stop disc into locking engagement with said key for setting said shaft in desired angular position.

'7. Shaft positioning appartaus comprising, in combination, a shaft to be positioned, a stop-disc mounted in adjusted relation on the shaft to be positioned, a key disposed in cooperative relation with said stop-disc, a cam device for moving the key towards the stop-disc to a limited extent, a slide bar for moving the key into engagement with said stop-disc, a common driving means, means for coupling said cam device to said driving means to effect the limited movement of said key, means for coupling said slide bar to said driving means to effect a further movement of said key, and means for coupling said stop-disc to said driving means for moving said disc into locking engagement with said key for setting said shaft in desired angular position.

8. Shaft positioning apparatus in accordance with the invention defined in claim '7 wherein each of the several coupling means consists of a gear which normally is disengaged from the driving means, and each gear is shifted in timed relation into coupling engagement with the driving means by means of a solenoid having its armature afiixed to the gear.

9. Shaft positioning apparatus in accordance with the invention defined in claim 7 wherein the slide bar has associated with it a stop member which, until the slide bar has been moved by actuation of its coupling means, prevents the actuation of the coupling means associated with the cam device.

l0. Shaft positioning apparatus comprising, in combination, a shaft to be positioned, a stopdisc mounted in adjusted relation on the shaft to be positioned, a key disposed in cooperative relation with said stop-disc, a selector drum for moving the key towards the stop-disc to a limited extent, a slide bar for moving the key intoengagement with said stop-disc, a carrier for the-slide :bar, a cam for actuating the slide bar carrier, at common driving means, means for coupling said drum to said driving means to effect the limited movement of said key, means for coupling said slide :bar cam to said driving means to eifect a further movement of said key, means movable with said cam for making the slide bar coupling means effective prior to the drum coupling means, and means for coupling said stop-disc to said driving means for moving said disc into locking engagement with said key for setting said shaft in desired angular position.

11. Mechanism for automatically and selectively adjusting .a device to one of a plurality of predetermined positions, comprising a plurality of stop-discs movable with the device each corresponding to one of said positions, a plurality of locking keys each adapted to cooperate with a corresponding stop-disc, key selector means operative to select the particular key which is to be effective, key actuating means for moving the selected key into operative relation with its cori responding stop-disc, an electric motor, a master gear driven by the motor, and means for actuat ing the key selector means, the key actuating means and the plurality of sto discs from the master gear in proper sequence whereby the key selector means is first operated to a predetermined position to select which the key actuating means is operated to cause the selected key to rest on the periphery of its associated stop-disc, and then said stop-disc is moved into locking engagement with the selected key at which time the device will assume its predetermined adjusted position.

12. Mechanism for automatically and selectively adjusting a device to one of a plurality of predetermined positions, comprising a plurality a particular key, after 

